Moulding chamber arrangement for a mould-string plant

ABSTRACT

Molding chamber arrangement ( 1 ) for a mold-string plant comprising a molding chamber ( 2 ) formed by a chamber bottom ( 3 ), a chamber ceiling ( 4 ) provided with one or more sand filling openings ( 22 ) communicating with a sand-feed system ( 14 ), two chamber side walls ( 5 ), a pressure plate ( 6 ) provided with an exchangeable pressure pattern plate having a pressure pattern ( 8 ) and being connected to a movement mechanism ( 9 ), a swingable plate ( 10 ) provided with an exchangeable swing pattern plate having a swing pattern ( 12 ) and being mounted for translational and swinging movement in order to open and close the molding chamber ( 2 ), allowing the pressure plate ( 6 ) to expel the produced molds, and further comprising means ( 13 ) for vertically moving the chamber ceiling ( 4 ) and sand-feed system ( 14 ) in unison, or the chamber bottom ( 3 ), or both, relative to the remainder of the molding chamber arrangement ( 1 ), thereby changing the height of the molding chamber. By this arrangement, the flexibility of the size of the produced molds, especially the heights of the produced molds, can be adjusted without changing the geometry of the sand feed system above the molding chamber in a time-saving manner.

TECHNICAL FIELD

The present invention relates to a moulding chamber arrangement for amould-string plant of the kind set forth in the preamble to claim 1.

BACKGROUND ART

In moulding chambers for mould-string plants of this kind it is known toprovide variable sizes of the moulding chamber by making the side wallsof the moulding chamber movable and adjusting the positioning of theside walls by means of a hydraulic system. A moulding chamber of thistype is known from EP 1 149 645 A1. A problem with a moulding chamber ofthis type is that it is not possible to use pattern plates that vary inthe height.

Furthermore, WO 2009/074838 discloses a moulding chamber arrangement fora mould-string plant, in which a variable size of the moulding chamberis provided by using adaptor plates for reducing the size of themoulding chamber. In connection with reduction of the height of themoulding chamber, the insertion of an adaptor plate on the upper wall ofthe moulding chamber increases the distance between the sand feed systemand the moulding chamber, whereby the sand flow into the mouldingchamber will be affected unfavourably. Moreover, it is very laboriousand time consuming to insert or remove adaptor plates in the chamberceiling because it requires the movement of very heavy components(adaptor plates of the above mentioned kind weigh several hundreds ofkg), and inevitable residue deposits of sand in the sand feed systemwill also leak into the moulding chamber during the insertion or removalof the adaptor plates.

Additionally, FR 2 196 865 discloses a sand moulding machine whereinsand moulds are formed by pressing pattern plates toward each other.After the sand moulds are formed the top plate is raised so that thesidewalls can tilt slightly and therefore not stick to the sand mouldwhen it is being expelled from the form chamber. Thus, even though thetop plate is movable vertically, the form chamber in which the sandmoulds are formed is not altered in size, and therefore in particularnot in the vertical direction. Accordingly, the volume of the formchamber is not altered.

U.S. Pat. No. 3,654,986 discloses a type of sand moulding machines thatoperates according to the so-called match plate principle, which employsmatch plates and flasks. The disclosed machine is equipped with a heightadjustable receiver table, which receives the finished moulds and levelsthem with a conveyor. The moulding chamber itself is not changed in sizeby the movement of the receiver table.

DISCLOSURE OF THE INVENTION

It is thus an object of the present invention to provide a mouldingchamber arrangement of the kind referred to above, by which it ispossible to provide an increased flexibility of the size of the producedmoulds in a way that does not adversely affect the sand flow into themoulding chamber, and which is quickly to adjust, in particular in theheight, with a minimum of manual work.

This and further objects is achieved with a moulding chamber arrangementfor a mould-string plant comprising: a moulding chamber formed by achamber bottom, a chamber ceiling provided with one or more sand fillingopenings communicating with a sand feed system, two chamber side walls,a pressure plate provided with an exchangeable pressure pattern platehaving a pressure pattern and being connected to a movement mechanism, aswingable plate provided with an exchangeable swing pattern plate havinga swing pattern and being mounted for translational and swingingmovement in order to open and close the moulding chamber, allowing thepressure plate to expel the produced moulds. The moulding chamberarrangement further comprises means for vertically moving the chamberceiling and sand-feed system in unison, or the chamber bottom, or both,relative to the remainder of the moulding chamber arrangement, therebychanging the height of the moulding chamber.

Since this arrangement comprises means for vertically moving the chamberceiling and sand-feed system in unison, relative to the remainder of themoulding chamber arrangement, it is possible to vary the heights of themoulds without changing the geometry of the sand feed system above themoulding chamber. It is thus possible to vary the height of the sandmoulds without adversely affecting the inflow of sand into the mouldingchamber during the formation of the moulds.

By the geometry of the sand feed system is meant any of the followingprocess parameters: The angle of the sides of the funnel, the height ofthe funnel, the size, especially the height, and form of thesand-filling opening, Furthermore, there are provided a number of airexhaust nozzles in the chamber ceiling of the moulding chamber in orderto ensure that air can escape from the moulding chamber while it isbeing filled with sand. The geometry, number, and placement of these airexhaust nozzles are also critical process parameters.

Since the inventive arrangement comprises means for vertically movingthe chamber ceiling and sand-feed system in unison, relative to theremainder of the moulding chamber arrangement, it is possible to varythe heights of the moulds without changing any of these criticalprocessing parameters.

By providing means for vertically moving the chamber ceiling andsand-feed system in unison, relative to the remainder of the mouldingchamber arrangement, a very time-saving shift in the production of sandmoulds having different sizes is achieved as compared to the laboriousexchange of adaptor plates in the ceiling of the moulding chamber knownin the prior art.

Since the geometry of the chamber ceiling and sand-feed system needs tobe unchanged in order to obtain an optimal running in the productionline; the only alternative to this is a complete rebuilding of the topof the machine, which would require a long and complicated rearrangementof rather heavy equipment, and it would therefore not be a flexible andeconomically favorable solution.

In a preferred embodiment, the arrangement further comprises means forchanging the horizontal extension of the moulding chamber in thedirection between the two chamber side walls. Hereby is achieved anarrangement wherein both the height and width of the moulding chambermay be adjusted to the needs of the user.

This is a tremendous practical advantage because most standard patternplates are manufactured in a number of standard sizes that vary inheight as well as in width, and many manufacturers hold many (oftenseveral thousands) such different pattern plates, and since thesepattern plates are rather expensive to manufacture, it is a hugeadvantage that they all can be used or re-used in a moulding chamberarrangement according to the invention. For example, it is commonpractice to use the so called A and B pattern plates, which are used insand moulding machines manufactured by DISA. The A plate has a width of600 mm and a height of 480 mm, while the B plate has a width of 650 mmand a height of 535 mm. Thus, a moulding chamber arrangement that canonly be adjusted in the height or the width cannot be used together withboth of these types of pattern plates.

Accordingly, a highly flexible moulding chamber arrangement is provided,which at the same time eliminates some of critical disadvantages of theprior art systems.

According to an embodiment of the moulding chamber arrangement, themeans for changing the horizontal extension of the moulding chamber inthe direction between the two chamber side walls comprises mounting ofone or two side wall wear plates. Preferably, the means for changing thehorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls comprises one or two side wall wear plates.This provides a convenient way of adjusting the horizontal extension ofthe moulding chamber between the two chamber side walls. The side wallwear plates are manually mounted using conventional mounting means.

An alternative embodiment of a moulding chamber arrangement according tothe invention may furthermore comprise two side wall wear plates, andthe means for changing the horizontal extension of the moulding chamberin the direction between the two chamber side walls may comprise meansfor changing the distance between the two side wall wear plates. Thesemeans could for example be manually operated means, e.g. means formanually moving the side wall wear plates using guide rods and fixingmeans like bolts and nuts.

In a further alternative embodiment according to the invention, themeans for changing the horizontal extension of the moulding chamber inthe direction between the two chamber side walls may comprise themounting of one or two side adaptor plates. These adaptor plates arepreferably placed on the chamber side walls behind a wear plate, so thatonly the wear plate will be in direct contact with the sand moulds. Inthis way a cheaper and easier way of adjusting the width of the mouldingchamber is provided, because while a wear plate has to be manufacturedof a material having some very special properties, there are less strictrequirements for the adaptor plates, because they are not directlyexposed to the sand in the moulding chamber.

A yet further embodiment of a moulding chamber arrangement in accordancewith the invention may comprise several sets of side adaptor plates,each set providing an individual reduced horizontal extension of themoulding chamber in the direction between the two chamber side walls.

Alternatively, the moulding chamber arrangement for a mould-string plantin accordance with an embodiment of the invention may comprise severalsets of side wall wear plates, each set providing an individual reducedhorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls.

In a preferred embodiment of a moulding chamber arrangement inaccordance with the invention, the means for changing the distancebetween the two chamber side wall wear plates may comprise at least oneside adaptor plate adapted to be mounted on at least one of the chamberside walls of the moulding chamber, preferably two adaptor plates ofequal thickness for mounting on each of the two chamber side walls, theside wall wear plates being mounted on said adaptor plates. By providingtwo adaptor plates of equal thickness behind a wear plate, a symmetricalreduction of the width of the moulding chamber is achieved, therebyprecluding axis stress on the piston means that drives the press plate.

In another preferred embodiment of a moulding chamber arrangement themeans for changing the distance between the two side wall wear platescomprises moving means for horizontally moving the chamber side wallsand side wall wear plates. These moving means may comprise a manuallyadjustable spindle, guide rods and fastening bolts or other manuallyadjustable movement means, such as a spindle or a rack pinion.

Preferably, the swing pattern and pressure pattern mounting plates havedimensions adapted to the possible reduced sizes of the mouldingchamber.

In another embodiment the moulding chamber arrangement may furthercomprise means for closing the possible gaps between the chamber sidewalls and/or chamber ceiling and chamber bottom.

Said means for closing the possible gaps between the chamber side wallsand/or chamber ceiling and chamber bottom may comprise loose insertsand/or fixed extensions of wear plates.

A preferred embodiment of a moulding chamber arrangement in accordancewith the invention may further comprise means for fixating the movableparts of the moulding chamber in the intended use positions.

The above mentioned and further objects of the invention are achieved bya method of changing the volume of a moulding chamber in a mould stringplant, said moulding chamber being delimited by a chamber bottom, achamber ceiling provided with one or more sand filling openingscommunicating with a sand-feed system, two chamber side walls, apressure plate provided with an exchangeable pressure pattern platehaving a pressure pattern and being connected to a movement mechanism, aswingable plate provided with an exchangeable swing pattern plate havinga swing pattern and being mounted for translational and swingingmovement in order to open and close the moulding chamber, allowing thepressure plate to expel the produced moulds, wherein the methodcomprises the step of

-   -   vertically moving the chamber ceiling and sand-feed system in        unison, or the chamber bottom, or both, relative to the        remainder of the moulding chamber arrangement, thereby changing        the height of the moulding chamber.

In a preferred embodiment, the method further comprises the step ofchanging the horizontal extension of the moulding chamber in thedirection between the two chamber side walls, whereby both the heightand width of the produced moulds is changed.

According to an embodiment of the method, the step of changing thehorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls may comprise the sub step of mounting of oneor two side wall wear plates.

According to an embodiment of the method, the step of changing thehorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls may comprise the sub step of changing thedistance between two side wall wear plates.

According to an embodiment of the method, the step of changing thehorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls may comprise the sub step of mounting of oneor two side adaptor plates.

The sub step of changing the distance between the two side wall wearplates may according to a preferred embodiment of the method comprisethe sub steps of:

Mounting at least one side adaptor plate on at least one of the chamberside walls of the moulding chamber, preferably two adaptor plates ofequal thickness on each of the two chamber side walls, and mounting theside wall wear plates on said adaptor plates.

According to an embodiment of the method, the step of changing thedistance between the two side wall wear plates comprises the step ofhorizontally moving the chamber side walls and side wall wear plates.

According to an embodiment, the method may further comprise the step ofproviding swing pattern and pressure pattern mounting plates havingdimensions adapted to the possible reduced sizes of the mouldingchamber.

According to an embodiment, the method may further comprise the step ofclosing the possible gaps between the chamber side walls and chamberceiling and chamber bottom.

According to an embodiment of the method, the step of closing thepossible gaps between the chamber side walls and chamber ceiling andchamber bottom may comprise the step of mounting or dismounting looseinserts and/or fixed extensions of wear plates.

According to an embodiment, the method further comprises the step offixating the movable parts of the moulding chamber in the intended usepositions.

According to an embodiment, the method may comprise the step ofsymmetrically changing the width and/or height of the produced moulds.

A second aspect of the invention pertains to a moulding chamberarrangement for a mould-string plant comprising: a moulding chamberformed by a chamber bottom, a chamber ceiling provided with one or moresand filling openings communicating with a sand-feed system, two chamberside walls, a pressure plate provided with a pressure pattern mountingplate and a pressure pattern and connected to a movement mechanism, aswingable plate provided with a swing pattern mounting plate and a swingpattern and mounted for translational and swinging movement in order toopen and close the moulding chamber, allowing the pressure plate toexpel the produced moulds, wherein the moulding chamber arrangementfurther comprises means for changing the vertical distance between thechamber ceiling and the chamber bottom.

In an embodiment according to the second aspect of the invention, saidmeans for changing the vertical distance between the chamber ceiling andthe chamber bottom is being provided in the form of a moving means forvertically moving the chamber ceiling and sand-feed system in unison,and/or the chamber bottom and mould transport arrangement in unison,relative to the remainder on the moulding chamber arrangement.

The moulding chamber arrangement for a mould-string plant may inaccordance with another embodiment of the second aspect of the inventionfurther comprise means for changing the distance between the two sidewall wear plates.

According to an embodiment of the second aspect of the invention, themeans for changing the distance between the two side wall wear platescomprising at least one side adaptor plate adapted to be mounted on atleast one of the chamber side walls of the moulding chamber, preferablytwo adaptor plates of equal thickness for mounting on each of the twochamber side walls, the side wall wear plates being mounted on saidadaptor plates.

According to yet another embodiment of the second aspect of theinvention, the means for changing the distance between the two side wallwear plates comprises moving means for horizontally moving the chamberside walls and side wall wear plates.

The moulding chamber arrangement may in accordance with an embodiment ofthe second aspect of the invention further comprise swing pattern andpressure pattern mounting plates having dimensions adapted to thepossible reduced sizes of the moulding chamber.

The moulding chamber arrangement may in accordance with an embodiment ofthe second aspect of the invention further comprise means for closingthe possible gaps between the chamber side walls and chamber ceiling andchamber bottom.

Said means may according to another embodiment of the second aspect ofthe invention comprise loose inserts and/or fixed extensions of wearplates.

The moulding chamber arrangement may according to another embodiment ofthe second aspect of the invention further comprise means for fixatingthe movable parts of the moulding chamber in the intended use positions.

It is understood that features of one of the aspects of the invention asdescribed above may be combined with embodiments of the other aspect ofthe invention in so far as they are compatible.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed part of the present description, the inventionwill be explained in more detail with reference to the exemplaryembodiments of a moulding chamber arrangement for a mould-string plantaccording to the invention shown in the drawings, in which:

FIG. 1 schematically shows a partly cut-away side view of a mouldingchamber arrangement in accordance with the present invention.

FIG. 2 shows a schematic cross section of the chamber arrangement alongthe line A-A in FIG. 1, showing the side and top walls in two differentpositions in the left-hand side and right-hand side of the figure,respectively.

FIGS. 3A, B, C and D show different configurations of means for closingthe gaps between the chamber side walls and top walls.

FIG. 4 shows a schematic cross section corresponding to FIG. 2, butshowing an alternative embodiment using adaptor plates for changing thewidth of the moulding chamber.

FIG. 5 shows a schematic cross section corresponding to FIG. 2 and FIG.4, but showing an alternative embodiment, in which both top wall andchamber bottom of the moulding chamber can be moved vertically in orderto change the height of the moulding chamber.

FIG. 6 shows a schematic illustration of a change from producing largersand moulds to producing smaller moulds.

FIGS. 7A-7C illustrate schematically different ways of reducing thewidth of the moulding chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown. The invention may however be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likereference numerals refer to like elements throughout. Like elements willthus not be described in detail with respect to the description of eachfigure.

The moulding chamber arrangement shown in FIG. 1 comprises a sand-feedsystem 14 for filling sand into the moulding chamber 2, said mouldingchamber 2 being delimited by two patterns 8, 12 and a chamber bottom 3and two chamber side walls 5, 24 shown in FIGS. 2-5 and a chamberceiling 4.

In the illustrated mould-string plant, the pressure pattern 8 is mountedon a pressure pattern mounting plate 7, which in turn is mounted on thepressure plate 6 connected to the pressure piston rod 9 for moving thiscombination of components in a horizontal direction for compacting thesand in the moulding chamber and for expelling the resulting sandmoulds. Correspondingly, the swing pattern 12 is connected to the swingpattern mounting plate 11 mounted on the swingable plate 10, which in awell-known manner is connected to a moving mechanism for horizontalmovement and swinging movement in order to be able to co-operate withthe pressure pattern for compacting the sand in the mould chamber 2, andto be moved horizontally and in a swinging movement out of the way forexpelling the produced moulds.

As can be seen in FIG. 1 and FIG. 2, a moving means in the form of a setof hydraulic piston cylinder units 13 is provided in order to be able tomove the chamber ceiling 4 with its ceiling wear plate 17 in thevertical direction, thereby changing the heights of the produced moulds.The hydraulic piston cylinder units 13 are configured for moving thecombination of ceiling wear plate 17, chamber ceiling 4, sand funnel 21and sand-filling system 14 in unison relative to the remainder of themoulding chamber arrangement 1.

In the embodiment shown in FIG. 2, a further flexibility is obtained byproviding a possibility of moving the chamber side walls 5 and side wallwear plates 16 in a horizontal direction, thereby varying the widths ofthe produced moulds.

As shown in FIG. 2, a number of bolts and nuts 25 are provided forfixing the chamber side walls 5 in the intended use positions, and thehorizontal movement of the chamber side walls 5 is guided by suitableguide rods.

Different ways of closing the potential openings in the corners of themoulding chamber are shown in FIGS. 3A-D. In FIG. 3A, an insert 19 ispositioned between the side wall wear plate 16 and the chamber ceilingwear plate 17 and removed when changing the size of the moulding chamberby lowering the chamber ceiling 4 and ceiling wear plate 17 and movingthe chamber side wall 5 and wear plate 16 as shown.

As shown in FIG. 3B, a corresponding removal of the insert 19 providesthe possibility of moving the chamber ceiling 4 and chamber ceiling wearplate 17 vertically, without moving the chamber side wall 5 and sidewall wear plate 16, thus only reducing the heights of the producedmoulds without changing the widths thereof.

FIG. 3C shows how an appropriate forming of the side wall wear plate 16to extend past the position of the chamber ceiling wear plate 17 andhaving an chamber ceiling 4 and chamber ceiling wear plate 17dimensioned to pass along the side wall wear plate 16, providing thepossibility of moving said chamber ceiling 4 and chamber ceiling wearplate 17 vertically along the side wall wear plate 16 in order to changethe heights of the produced moulds.

In FIG. 3D it is shown how an insert 20 can be formed in order toprovide the possibility of two different sizes of the produced moulds,where both heights and widths of the produced moulds are changed andwhere the insert 20 may be permanently installed inside the mouldingchamber arrangement. In the first position shown to the left in FIG. 3D,the chamber ceiling wear plate 17 is positioned in continuation of ahorizontal part of the insert 20, and correspondingly the side wall wearplate 16 is positioned in continuation of a vertical part of said insert20. In the second position shown in FIG. 3D to the right, the two wearplates 16 and 17 are positioned adjacent.

In FIG. 4 it is shown how the widths and heights of the produced mouldscan be changed, the left side of FIG. 4 showing high and wide producedmoulds and the right side showing low and narrow produced moulds. To theleft, the chamber ceiling 4 with wear plate 17 is positioned in an upperposition, and the side wall wear plate 16 has a height corresponding tothis position of the chamber ceiling wear plate 17. To the right, thechamber ceiling 4 and chamber ceiling wear plate 17 have been moved to alower position and the side wall wear plate 16 has been replaced by anadaptor plate 23 and a side wall wear plate 16 having a heightcorresponding to the position of the chamber ceiling wear plate 17.Different sizes of adaptor plates 23 and corresponding side wall wearplates 16 can provide several different compositions of widths andheights of the produced moulds.

In FIG. 5, which to a major part corresponds to FIG. 2, it is shown howa further movement mechanism shown at the bottom in the form ofhydraulic piston cylinder units 13 is provided to move the chamberbottom 3 and chamber bottom wear plate 18 in the vertical direction inorder to change the heights of the produced moulds. As shown in FIG. 5,a removable insert 19 is provided between the side wall wear plate 16and the chamber bottom wear plate 18 and different configurationscorresponding to the FIGS. 3A to 3D can naturally be envisaged also inthis connection.

FIG. 6 shows schematically how a moulding chamber arrangement accordingto an embodiment of the invention can be switched from producing sandforms 26 of a larger height and width to producing sand moulds 27 of asmaller height and width. The height of the sand moulds is reduced byvertically lowering the chamber ceiling 4 and sand-feed system 14 (ofwhich only the funnel 21 is shown) in unison relative to the remainderof the moulding chamber arrangement 1. As illustrated, a ceiling wearplate 17 is attached to the chamber ceiling 4. For illustrationalpurposes the ceiling wear plate 17 is illustrated apart from the chamberceiling 4 in order to show that it is provided with one or more sandfilling openings 22 providing a connection between the funnel 21 of thesand-feed system 14 (not shown) of the moulding machine and the mouldingchamber 2. This ceiling wear plate 17 is attached to the chamber ceiling4 using conventional mounting means, preferably self-locking mountingmeans alleviating the use of screws or bolts.

Also the chamber sidewalls 5 are equipped with a sidewall wear plate 16,which is attached to the chamber sidewall 5 using conventional mountingmeans, preferably self-locking mounting means alleviating the use ofscrews or bolts. The illustrated sidewall 5 is sometimes referred to asa so called “base plate”, which in the illustrated embodiment is movablewith respect to the side frame 28 of the moulding chamber arrangement 1.

In order to change the horizontal extension of the moulding chamber 2 inthe direction between the two chamber side walls 5, the moulding chamberarrangement further comprises a spindle 29 and guide rods 30, which areoperatively connected to the chamber side wall 5. The spindle ispreferably equipped with a turning wheel (not shown). Thus, by manuallyturning the wheel a predetermined number of times, it is possible toadjust the width of the moulding chamber 2 very accurately. Thearrangement is furthermore equipped with means for locking the chambersidewalls 5 at the desired position in order to preclude that they willmove during the very high pressures applied during the formation of thesand moulds.

The pressure plate arrangement shown in FIG. 6 comprises a pressureplate 6, on which a pressure pattern mounting plate 7 is mounted, saidpressure pattern mounting plate 7 being adapted to the size of themoulding chamber 2 after the adjustment of the height and width of themoulding chamber 2. On the pressure pattern mounting plate is mounted apressure pattern plate 31 having a pattern 8. This pressure patternplate 31 could in one embodiment be a so called A plate mentionedearlier, while for example a so called B plate could have been used inthe previous production cycle for producing the sand moulds 26. Similarchanges are needed for the not illustrated swing plate arrangement whenswitching from producing larger sand forms to producing the smaller sandforms.

In FIG. 7A is schematically illustrated an opening of an embodiment of amoulding chamber 2, wherein the width is reduced by moving the chamberside wall 5 (or the so called base plates 5) and the side wall wearplate 16 with respect to the side frame 28 of the moulding chamber 2.This movement is caused by manually turning the turning wheel 32, andthereby the spindle 29 to which it is connected, a desired number ofturns in order to achieve the desired reduction of the width of themoulding chamber 2.

In FIG. 7B is illustrated an alternative way of reducing the width ofthe moulding chamber 2 by mounting a thicker chamber sidewall plate 5(i.e. a thicker base plate 5) behind the side wall wear plate 16 in eachside of the moulding chamber using the conventional mounting means, i.e.preferably self-locking mounting means, alleviating the need for screwsand bolts.

As illustrated in FIG. 7C, a set of side wall adaptor plates 23 can beused for reducing the width of the moulding chamber 2 from one standardwidth to another. Correspondingly, two side wall adaptor plates 23,preferably of equal thickness, are provided for installing on thechamber side walls 5 of the moulding chamber 2. The sides of the sidewall adaptor plates 23 facing the mould to be produced are provided withside wall wear plates 16 mounted on the side wall adaptor plates 16using conventional mounting means for the side wall wear plates 16. Themounting of the side wall adaptor plates 23 inside the moulding chamber2 is preferably performed by using the mounting means for the side wallwear plates 16 for the moulding chamber 2, and this is made possible byremoving the side wall wear plates 16 before inserting the side walladaptor plates 23.

In the embodiments illustrated in FIGS. 7A-7C, the height of themoulding chamber has also been reduced to the desired size. Furthermore,in all of the embodiments schematically illustrated in FIGS. 7A-7C thewidth has been reduced by the same size in both sides of the mouldingchamber 2. This will give a more symmetrical application of thecompression force on the pressure and swing plates 6 and 10.

In general, it will be preferred to provide a symmetrical change ofwidth and also height of the produced mould in order to maintain acorrespondence between the axis of the pressure piston 9 and the gravitycentre of the mould produced in the mould chamber 2 in order to avoidunsymmetrical forces in the system during compacting of the sand moulds.

Above, the invention has been described in connection with somepreferred embodiments, and it will be evident for a person skilled inthe art that several modifications can be performed within the scope ofthe following claims without departing from the general concept of thepresent invention. Such modifications and deviations include combiningdifferent movement mechanisms for the movement of the chamber ceilingand chamber bottom and movement mechanisms for moving the chamber sidewalls, and also the possibility of deviating from the above-mentionedpreferred symmetrical change of the moulding chamber dimensions.

LIST OF REFERENCE NUMBERS

1 moulding chamber arrangement,

2 moulding chamber,

3 chamber bottom,

4 chamber ceiling,

5 chamber side wall, or base plate,

6 pressure plate,

7 pressure pattern mounting plate,

8 pressure pattern,

9 pressure piston rod,

10 swingable plate,

11 swing pattern mounting plate,

12 swing pattern,

13 hydraulic piston cylinder unit,

14 sand-feed system,

16 side wall wear plate,

17 ceiling wear plate,

18 chamber bottom wear plate,

19 insert,

20 insert,

21 sand funnel,

22 sand filling openings,

23 side wall adaptor plate,

24 chamber side wall,

25 bolts and nuts, movement means for moving the chamber side plate,

26 large sand forms,

27 small sand forms,

28 side frame of moulding chamber,

29 spindle

30 guiding rod,

31 pressure pattern plate, and

32 turning wheel.

The invention claimed is:
 1. Moulding chamber arrangement for amould-string plant comprising: a moulding chamber formed by a chamberbottom, a chamber ceiling provided with one or more sand fillingopenings communicating with a sand feed system, two chamber side walls,a pressure plate provided with an exchangeable pressure pattern platehaving a pressure pattern and being connected to a movement mechanism, aswingable plate provided with an exchangeable swing pattern plate havinga swing pattern and being mounted for translational and swingingmovement in order to open and close the moulding chamber, allowing thepressure plate to expel the produced moulds, means for changing thehorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls, characterised by further comprising meansfor vertically moving the chamber ceiling and sand-feed system inunison, or the chamber bottom, or both, relative to the remainder of themoulding chamber arrangement, thereby changing the height of themoulding chamber for accommodating pattern plates of standard sizes,which wary in height as well as in width.
 2. Moulding chamberarrangement in accordance with claim 1, characterized by means for onlyvertically moving the chamber ceiling and sand-feed system in unison,relative to the remainder of the moulding chamber arrangement, therebychanging the height of the moulding chamber.
 3. Moulding chamberarrangement in accordance with claim 1, characterized by means for onlyvertically moving the chamber bottom, relative to the remainder of themoulding chamber arrangement, thereby changing the height of themoulding chamber.
 4. Moulding chamber arrangement for a mould-stringplant in accordance with claim 1, wherein the means for changing thehorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls comprises mounting of one or two side wallwear plates.
 5. Moulding chamber arrangement for a mould-string plant inaccordance with claim 1, further comprising two side wall wear plates,and wherein the means for changing the horizontal extension of themoulding chamber in the direction between the two chamber side wallscomprises means for changing the distance between the two side wall wearplates.
 6. Moulding chamber arrangement for a mould-string plant inaccordance with claim 1, wherein the means for changing the horizontalextension of the moulding chamber in the direction between the twochamber side walls comprises mounting of one or two side adaptor plates.7. Moulding chamber arrangement for a mould-string plant in accordancewith claim 1, characterized by comprising several sets of side adaptorplates, each set providing an individual reduced horizontal extension ofthe moulding chamber in the direction between the two chamber sidewalls.
 8. Moulding chamber arrangement for a mould-string plant inaccordance with claim 1, characterized by comprising several sets ofside wall wear plates, each set providing an individual reducedhorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls.
 9. Moulding chamber arrangement inaccordance with claim 5, characterised by the means for changing thedistance between the two side wall wear plates comprising at least oneside adaptor plate adapted to be mounted on at least one of the chamberside walls of the moulding chamber, preferably two adaptor plates ofequal thickness for mounting on each of the two chamber side walls, theside wall wear plates being mounted on said adaptor plates.
 10. Mouldingchamber arrangement in accordance with claim 5, characterised by themeans for changing the distance between the two side wall wear platescomprising moving means for horizontally moving the chamber side wallsand side wall wear plates.
 11. Moulding chamber arrangement inaccordance with claim 1, characterised by further comprising swingpattern and pressure pattern mounting plates having dimensions adaptedto the possible reduced sizes of the moulding chamber.
 12. Mouldingchamber arrangement in accordance with claim 1, characterised by furthercomprising means for closing the possible gaps between the chamber sidewalls and chamber ceiling and chamber bottom.
 13. Moulding chamberarrangement in accordance with claim 12, characterised by said meanscomprising loose inserts and/or fixed extensions of wear plates. 14.Moulding chamber arrangement in accordance with claim 1, characterisedby further comprising means for fixating the movable parts of themoulding chamber in the intended use positions.
 15. A method of changingthe volume of a moulding chamber in a mould string plant, said mouldingchamber being delimited by a chamber bottom, a chamber ceiling providedwith one or more sand filling openings communicating with a sand feedsystem, two chamber side walls, a pressure plate provided with anexchangeable pressure pattern plate having a pressure pattern and beingconnected to a movement mechanism, a swingable plate provided with anexchangeable swing pattern plate having a swing pattern and beingmounted for translational and swinging movement in order to open andclose the moulding chamber, allowing the pressure plate to expel theproduced moulds, wherein the method comprises the steps of: changing thehorizontal extension of the moulding chamber in the direction betweenthe two chamber side walls, and vertically moving the chamber ceilingand sand-feed system in unison, or the chamber bottom, or both, relativeto the remainder of the moulding chamber arrangement, thereby changingthe height of the moulding chamber for accommodating pattern plates ofstandard sizes, which wary in height as well as in width.
 16. A methodin accordance with claim 15, comprising the step of vertically movingonly the chamber ceiling and sand-feed system in unison, relative to theremainder of the moulding chamber arrangement, thereby changing theheight of the moulding chamber.
 17. A method in accordance with claim15, comprising the step of vertically moving only the chamber bottom,relative to the remainder of the moulding chamber arrangement, therebychanging the height of the moulding chamber.
 18. A method in accordancewith claim 15, wherein the step of changing the horizontal extension ofthe moulding chamber in the direction between the two chamber side wallscomprises the sub step of mounting of one or two side wall wear plates.19. A method in accordance with claim 15, wherein the step of changingthe horizontal extension of the moulding chamber in the directionbetween the two chamber side walls comprises the sub step of changingthe distance between two side wall wear plates.
 20. A method inaccordance with claim 15, wherein the step of changing the horizontalextension of the moulding chamber in the direction between the twochamber side walls comprises the sub step of mounting of one or two sideadaptor plates.
 21. A method in accordance with claim 20, wherein thesub step of changing the distance between the two side wall wear platescomprises the sub step of mounting at least one side adaptor plate on atleast one of the chamber side walls of the moulding chamber, preferablytwo adaptor plates of equal thickness on each of the two chamber sidewalls, and mounting the side wall wear plates on said adaptor plates.22. A method in accordance with claim 20, wherein the step of changingthe distance between the two side wall wear plates comprising the stepof horizontally moving the chamber side walls and side wall wear plates.23. A method in accordance with claim 15, further comprising the step ofproviding swing pattern and pressure pattern mounting plates havingdimensions adapted to the possible reduced sizes of the mouldingchamber.
 24. A method in accordance with claim 15, further comprisingthe step of closing the possible gaps between the chamber side walls andchamber ceiling and chamber bottom.
 25. A method in accordance withclaim 24, wherein step of closing the possible gaps between the chamberside walls and chamber ceiling and chamber bottom comprising the step ofmounting or dismounting loose inserts and/or fixed extensions of wearplates.
 26. A method in accordance with claim 15, further comprising thestep of fixating the movable parts of the moulding chamber in theintended use positions.
 27. A method in accordance with claim 15,comprising the step of symmetrically changing the width and/or height ofthe produced moulds.